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Wits Researchers have demonstrated a new quantum approach for sharing a secret amongst many parties, setting a new record for the highest dimensions and parties to date.

Researchers at the University of the Witwatersrand in Johannesburg, South Africa, have demonstrated a record setting quantum protocol for sharing a secret amongst many parties. The team created an 11-dimensional quantum state and used it to share a secret amongst 10 parties. By using quantum tricks, the secret can only be unlocked if the parties trust one another. The work sets a new record for the dimension of the state (which impacts on how big the secret can be) and the number of parties with whom it is shared and is an important step towards distributing information securely across many nodes in a quantum network.

Laser & Photonics Reviews published online the research by the Wits team led by Professor Andrew Forbes from the School of Physics at Wits University. In their paper titled: Experimental Demonstration of 11-Dimensional 10-Party Quantum Secret Sharing, the Wits team beat all prior records to share a quantum secret.

The life-givers of integrated circuits and quantum devices in silicon are small structures made from patches of foreign atoms called dopants. The dopant structures provide charge carriers that flow through the components of the circuit, giving the components their ability to function. These days the dopant structures are only a few atoms across and so need to be made in precise locations within a circuit and have very well-defined electrical properties. At present manufacturers find it hard to tell in a non-destructive way whether they have made their devices according to these strict requirements. A new imaging paradigm promises to change all that.

The imaging mode called broadband electric force microscopy, developed by Dr. Georg Gramse at Keysight technologies & JKU uses a very sharp probe that sends into a silicon chip, to image and localize structures underneath the surface. Dr. Gramse says that because the microscope can use waves with many frequencies it can provide a wealth of previously inaccessible detail about the electrical environment around the dopant structures. The extra information is crucial to predicting how well the devices will ultimately perform.

The imaging approach was tested on two tiny dopant structures made with a templating process which is unique in achieving atomically sharp interfaces between differently doped regions. Dr. Tomas Skeren at IBM produced the world’s first electronic diode (a circuit component which passes current in only one direction) fabricated with this templating process, while Dr. Alex Kölker at UCL created a multilevel 3D with atomic scale precision.

1. Dark horses of QC emerge: 2020 will be the year of dark horses in the QC race. These new entrants will demonstrate dominant architectures with 100–200 individually controlled and maintained qubits, at 99.9% fidelities, with millisecond to seconds coherence times that represent 2x\u200a-3x improved qubit power, fidelity and coherence times. These dark horses, many venture-backed, will finally prove that resources and capital are not sole catalysts for a technological breakthrough in quantum computing.”,” protected”:false},” excerpt”:{“rendered”:”

Quantum computing will represent the most fundamental acceleration in computing power that we have ever encountered, leaving Moore’s law in the dust.

A quintillion calculations a second. That’s one with 18 zeros after it. It’s the speed at which an exascale supercomputer will process information. The Department of Energy (DOE) is preparing for the first exascale computer to be deployed in 2021. Two more will follow soon after. Yet quantum computers may be able to complete more complex calculations even faster than these up-and-coming exascale computers. But these technologies complement each other much more than they compete.

It’s going to be a while before quantum computers are ready to tackle major scientific research questions. While quantum researchers and scientists in other areas are collaborating to design quantum computers to be as effective as possible once they’re ready, that’s still a long way off. Scientists are figuring out how to build qubits for quantum computers, the very foundation of the technology. They’re establishing the most fundamental quantum algorithms that they need to do simple calculations. The hardware and algorithms need to be far enough along for coders to develop operating systems and software to do scientific research. Currently, we’re at the same point in quantum computing that scientists in the 1950s were with computers that ran on vacuum tubes. Most of us regularly carry computers in our pockets now, but it took decades to get to this level of accessibility.

In contrast, exascale computers will be ready next year. When they launch, they’ll already be five times faster than our fastest computer – Summit, at Oak Ridge National Laboratory’s Leadership Computing Facility, a DOE Office of Science user facility. Right away, they’ll be able to tackle major challenges in modeling Earth systems, analyzing genes, tracking barriers to fusion, and more. These powerful machines will allow scientists to include more variables in their equations and improve models’ accuracy. As long as we can find new ways to improve conventional computers, we’ll do it.

Can a Quantum Strategy Help Bring Down the House?

In some versions of the game blackjack, one way to win against the house is for players at the table to work as a team to keep track of and covertly communicate amongst each other the cards they have been dealt. With that knowledge, they can then estimate the cards still in the deck, and those most likely to be dealt out next, all to help each player decide how to place their bets, and as a team, gain an advantage over the dealer.

This calculating strategy, known as card-counting, was made famous by the MIT Blackjack Team, a group of students from MIT, Harvard University, and Caltech, who for several decades starting in 1979, optimized card-counting and other techniques to successfully beat casinos at blackjack around the world — a story that later inspired the book “Bringing Down the House.”

A quantum-mechanical version of the ancient board game go has been demonstrated experimentally by physicists in China. Using entangled photons, the researchers placed go pieces (called stones) in quantum superpositions to vastly increase the complexity of the game. They foresee the technology serving as the ultimate test for machine players that use ever more sophisticated artificial intelligence (AI).

Time travel movies have different rules about what happens when you start messing around with the timeline. If you’ve ever wondered which ones make the most sense, we may now have an answer. According to experiments using a quantum time travel simulator, reality is more or less “self-healing,” so changes made to the past won’t drastically alter the future you came from – at least, in the quantum realm.

The classic Back to the Future rules of time travel say that whatever you change in the past can have huge effects on the future. That’s why Marty McFly can almost erase his own existence by accidentally stopping his parents from meeting, and why Biff Tannen can get rich by giving his younger self a book of sports scores to bet on.

Other movies handle things differently. In Avengers: Endgame, the superheroes travel back in time to steal versions of the Infinity Stones out of different time periods to revive their fallen friends (look, it doesn’t make much sense unless you’ve seen all 20-something movies). Anyway, they can dabble in the past without ruining the future because the universe has a knack for correcting those paradoxes so that both versions of events did happen.

Nationwide effort to build quantum networks and usher in new era of communications.

In a news conference today at the University of Chicago, the U.S. Department of Energy unveiled a report that lays out a blueprint strategy for the development of a national quantum internet, bringing the United States to the forefront of the global quantum race and ushering in a new era of communications. This report provides a pathway to ensure the development of the National Quantum Initiative Act, which was signed into law by President Trump in December 2018.

Around the world, consensus is building that a system to communicate using quantum mechanics represents one of the most important technological frontiers of the 21st century. Scientists now believe that the construction of a prototype will be within reach over the next decade.